One of the least desirable chores in cat ownership is cleaning the cat litter box. The most common litter box for a house cat is a square or rectangle-shaped plastic tub which is filled with urine-absorbent litter material. The litter material is usually either clay or granular cellulose. The litter material is usually sifted after a particular period of use, such as a few days, with a hand held scoop.
Other cleaning solutions consist of disposable cat litter box liners that are made of paper or plastic, able to be folded into a bag like configuration to dispose of the entire cat litter in the pan at any given time. U.S. Pat. No. 5,488,929 discloses an example of this type of cat litter pan liner. Disposable cat litter boxes have also been created, usually consisting of a single sheet of water resistant corrugated cardboard. As disclosed in U.S. Pat. No. 5,566,641, the litter box is a one-time use, allowing a user to throw away everything in the box, not just the used litter but any leftover unused litter as well.
While U.S. Pat. No. 5,121,712 discloses a liner that is perforated to allow sifting of used litter so unused litter can be returned to the litter box, the liner is made of plastic, which cats do not like. For whatever reason, cats are uncomfortable walking on plastic sheeting such that this type of perforate plastic liner can result in a cat not using the litter box.
It is desirable to not waste the unused cat litter, but be able to easily separate and remove the animal excrement and “used” litter and do so in a manner that is not repugnant to a cat.